In shops, supermarkets, office premises and industrial halls, there is often a to need to be able to suspend light fittings over a certain floor position, and at a certain height from the floor, to obtain the desired illumination of the room. Usually, the suspension takes place by suspending the fittings by lines or wires from a false ceiling that consists of a framework of metal profiles with ceiling panels fitted into the framework. A problem with such a suspension is that the ceiling panels, as a rule, have a bending resistance that is too low to allow the suspension lines to be attached directly to the panels, since this would result in sagging of the ceiling, for which reason the suspension lines have to be attached to the framework of metal profiles. Light fittings should normally be aligned in a certain fashion in the horizontal plane, and should maintain this alignment also after installation. In order to be able to attain the desired alignment stability for a mounted light fitting, several suspension points in the metal profiles of the false ceiling and several suspension lines are required for each light fitting. In order to enable the light fitting to be suspended at an optional distance from the floor and in a desired alignment relative to the floor plane, preferably in parallel thereto, each suspension line either has to be equipped with a suitable length-adjusting device or cut to length during the installation.
In rooms without a false ceiling, light fittings can be suspended directly from the ceiling. Also in this case it has to be possible to attach the suspension lines to sufficiently bending resistant portions of the ceiling, for example to roof beams or beam elements of a corrugated sheet metal roof. With suspension devices according to prior art, it is often difficult or impossible to attach the suspension lines at optimal points in the ceiling, and to simultaneously get the light fitting suspended over a desired floor position in the room in an angularly stable manner, without requiring a plurality of suspension lines and length-adjusting devices, or cutting to length of the suspension lines before the suspension.